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141.
142.
Y Tsutsumi T Kihira S Tsunoda H Kamada S Nakagawa Y Kaneda T Kanamori T Mayumi 《Canadian Metallurgical Quarterly》1996,278(3):1006-1011
We have reported that chemical modification of tumor necrosis factor-alpha (TNF-alpha) with polyethylene glycol (PEG) markedly increases its antitumor potency without any adverse side effects. MPEG-TNF-alpha, especially, in which 56% of the lysine amino groups of TNF-alpha are coupled with PEG, exhibits 100-fold more antitumor activity in vivo than native TNF-alpha in the Meth-A murine sarcoma model. In this study, we investigated the pharmacokinetics of PEG-modified TNF-alpha with various molecular sizes to clarify the mechanisms of the enhanced antitumor potency of MPEG-TNF-alpha. The plasma half-lives of modified TNF-alpha increased with increasing molecular size. The decreased plasma clearance of modified TNF-alpha was partially caused by the shielding effect of the proteolytic sites in TNF-alpha by the attached PEG and the decreased transport from blood to various tissues. Almost all native TNF-alpha was uniformly distributed to the kidney and reticuloendothelial system within 1 hr of an intravenous administration, and rapidly disappeared from these tissues at 3 hr. However, very little native TNF-alpha was transported into the tumor. The absolute distributed amount and distribution profile of modified TNF-alpha to tissues other than the tumor were the same as those of native TNF-alpha, whereas the plasma levels of the modified TNF-alpha were higher than plasma levels of the native TNF-alpha. The tumor distribution of modified TNF-alpha was markedly enhanced compared with native TNF-alpha and gradually increased over time. About 9-fold more MPEG-TNF-alpha was distributed to the tumor than native TNF-alpha. Thus, we found that the marked increase in the antitumor potency of PEG-modified TNF-alpha resulted from the enhanced blood residency and tumor accumulation. The antitumor effect of MPEG-TNF-alpha against sarcoma-180 other than Meth-A fibrosarcoma was also about 100 times greater than that of native TNF-alpha when systemically administered. The optimal PEGylation of TNF-alpha facilitated its antitumor potency and MPEG-TNF-alpha may be useful systemic antitumor therapeutic drug. 相似文献
143.
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145.
M Kohno K Yokokawa K Yasunari H Kano T Horio T Takeda 《Canadian Metallurgical Quarterly》1995,44(1):10-12
This study was conducted to compare the tensile bond strength at the two interfaces of the "sandwich technique". 48 hours after the specimens were tested, using Hounsfield tensometer. Load was gradually applied on to the specimen till the bond at the interface failed. The load at which the bond failed was recorded and analysed for statistical significance. From the present study it can be concluded that the bond between glass ionomer and dentine is better than the bond between glass ionomer and composite resin. 相似文献
146.
Facial expression recognition of a speaker using front-view face judgment, vowel judgment, and thermal image processing 总被引:1,自引:1,他引:0
Tomoko Fujimura Yasunari Yoshitomi Taro Asada Masayoshi Tabuse 《Artificial Life and Robotics》2011,16(3):411-417
For facial expression recognition, we selected three images: (i) just before speaking, (ii) speaking the first vowel, and
(iii) speaking the last vowel in an utterance. In this study, as a pre-processing module, we added a judgment function to
distinguish a front-view face for facial expression recognition. A frame of the front-view face in a dynamic image is selected
by estimating the face direction. The judgment function measures four feature parameters using thermal image processing, and
selects the thermal images that have all the values of the feature parameters within limited ranges which were decided on
the basis of training thermal images of front-view faces. As an initial investigation, we adopted the utterance of the Japanese
name “Taro,” which is semantically neutral. The mean judgment accuracy of the front-view face was 99.5% for six subjects who
changed their face direction freely. Using the proposed method, the facial expressions of six subjects were distinguishable
with 84.0% accuracy when they exhibited one of the intentional facial expressions of “angry,” “happy,” “neutral,” “sad,” and
“surprised.” We expect the proposed method to be applicable for recognizing facial expressions in daily conversation. 相似文献
147.
Rotation of a single cell is an indispensable cell manipulation technique for genetic studies and clinical applications. Conventional contact manipulation methods for rotation of a cell use complex control systems and tools, while conventional non-contact manipulation methods have limitations regarding the operating space or range of the rotated cell size. Here, we report on a convenient, non-contact, and open space method for a wide range of single cell sizes (micrometer scale to millimeter scale) rotating in a vertical plane (out-of-plane) of an open space. This method uses a vertical microscale recirculation zone for capturing and rotating the cell. We fabricated a micro-orifice on the surface of a microfluidic chip to generate the micro-recirculation zone and then carried out experiments on vertical rotations of Xenopus oocyte, embryoid body, brine shrimp oocyte, and zebrafish oocyte using this chip. We demonstrated the rotation of four types of cells in the vertical plane between the air–liquid interface and the top surface of the microfluidic chip; then, we conducted a simulation to analyze the dynamics of the vertical rotation of the Xenopus oocyte qualitatively. Our results indicated rotation speed of the four types of cells was controllable by the micro-recirculation zone. The size and density of oocytes also affected the process of capturing and rotation. We expect this method opens new research opportunities in three-dimensional cell manipulation, imaging, and analysis. 相似文献
148.
Nakhostin M Baba M Itoga T Oishi T Unno Y Kamada S Okuji T 《Radiation protection dosimetry》2008,129(4):426-430
The use of the parallel-plate avalanche counter for slow-neutron counting is described. The choice of a suitable neutron converter is discussed on the basis of Monte Carlo simulation, and some experimental results are shown. Excellent gamma-insensitivity, high rate capability, possibility of construction in large sensitive area and low production cost are among the promising features of this neutron detector. 相似文献
149.
Takayuki Marutani Kodai Nishino Tomoyuki Miyaji Keisuke Kamada Koji Ohura Yoshiaki Kiso Hidehito Mukai 《International journal of molecular sciences》2021,22(8)
Mitocryptides are a novel family of endogenous neutrophil-activating peptides originating from various mitochondrial proteins. Mitocryptide-2 (MCT-2) is one of such neutrophil-activating peptides, and is produced as an N-formylated pentadecapeptide from mitochondrial cytochrome b. Although MCT-2 is a specific endogenous ligand for formyl peptide receptor 2 (FPR2), the chemical structure within MCT-2 that is responsible for FPR2 activation is still obscure. Here, we demonstrate that the N-terminal heptapeptide structure of MCT-2 with an N-formyl group is the minimum structure that specifically activates FPR2. Moreover, the receptor molecule for MCT-2 is suggested to be shifted from FPR2 to its homolog formyl peptide receptor 1 (FPR1) by the physiological cleavages of its C-terminus. Indeed, N-terminal derivatives of MCT-2 with seven amino acid residues or longer caused an increase of intracellular free Ca2+ concentration in HEK-293 cells expressing FPR2, but not in those expressing FPR1. Those MCT-2 derivatives also induced β-hexosaminidase secretion in neutrophilic/granulocytic differentiated HL-60 cells via FPR2 activation. In contrast, MCT-2(1–4), an N-terminal tetrapeptide of MCT-2, specifically activated FPR1 to promote those functions. Moreover, MCT-2 was degraded in serum to produce MCT-2(1–4) over time. These findings suggest that MCT-2 is a novel critical factor that not only initiates innate immunity via the specific activation of FPR2, but also promotes delayed responses by the activation of FPR1, which may include resolution and tissue regeneration. The present results also strongly support the necessity of considering the exact chemical structures of activating factors for the investigation of innate immune responses. 相似文献
150.
Shunsuke Kurosawa Akihiro Yamaji Jan Pejchal Yuui Yokota Yuji Ohashi Kei Kamada Akira Yoshikawa 《Journal of Materials Science》2017,52(10):5531-5536
Li-containing materials can be applied as neutron scintillators, and LiBaF3 can discriminate neutron and gamma rays. Moreover, LIF/LiBaF3 can have higher cross section of thermal-neutron capture compared with LiBaF3. In this study, LiF (82.5 mol%) and (Ba1?x RE x )F2 (17.5 mol%, RE = Ce and Eu, x = 0.002) eutectic crystals, LiF/RE:LiBaF3, were grown by the micropulling down method with different pulling rates (growth rate) in order to observe the eutectic structure. Lamellar microstructure was formed for each pulling rate. LiF/Ce:LiBaF3 excited by 5.5-MeV alpha rays had a broad peak at ~350 nm corresponding to 5d–4f transition of Ce3+. On the other hand, LiF/Eu:LiBaF3 had two scintillation processes; a sharp emission was originated from 6P7/2 → 8S7/2 transitions in the 4f electronic configuration of Eu2+ at 360 nm, and a broad one was attributed to Eu2+ trapped exciton recombination at 400–450 nm. Since scintillation light was observed for these materials, these scintillators are sensitive to neutrons. 相似文献